Akerlof and Yellin, "New Mothers, Not Married: Technology shock, the demise of shotgun marriage, and the increase in out-of-wedlock births" The Brookings Review, Fall 1996 Vol. 14 No. 4, Pages 18-21.

Also see George A. Akerlof, Janet L. Yellin, J. L., & Michael L. Katz, "An Analysis of Out-of-Wedlock Childbearing in the United States," 111 Q. J. Econ. 277 (1996)